The exemplary embodiment relates to spatial characterization of imaging systems and finds particular application in connection with a system and method for configuring an imaging system used for determining the spatial layout of product content of a product facility, such as a store.
Retail chains, such as pharmacy, grocery, home improvement, and others, may have a set of product facilities, such as stores, in which products are presented on product display units, such as shelves, cases, and the like. Product information is generally displayed close to the product, on preprinted product labels. The product labels indicate the price of the item and generally include a unique identifier for the product, e.g., in the form of a barcode, which is often used by the store for restocking and other purposes. The product locations often vary across each of the stores in a chain. Thus, it is often desirable to map each store individually in order to know the exact locations of the products.
Current approaches for documenting product locations on shelves include sending one or more persons through the store taking pictures along the store aisles with a mobile device, such as a cell phone camera or using webcams mounted throughout the store. Post-processing of the captured images is then used in an attempt to identify each product and its location on a shelf. In many applications, such simple, un-calibrated, and low cost surveillance cameras are more than sufficient. However, there are many applications where more detailed analysis is desired, such as for the recognition of barcodes. Knowledge about the characteristics of the imaging system and accurate configuration of the imaging system would be particularly useful for such fine-grained tasks. This would help processing, such as simplifying the algorithms used, improving robustness, providing predictable inputs for analysis, and the like.
Existing calibration procedures using standard or special targets for single monocular or stereo-vision cameras are described, for example, in Zhengyou Zhang, “Flexible Camera Calibration By Viewing a Plane From Unknown Orientations,” ICCV '99, pp. 666-673 (1999) and U.S. Pub. No. 20130342706. However, such systems often lack the ability to deal with more complex imaging systems, such as multi-camera imaging systems which may need to be reconfigured due to changes in the imaging task, such as differences in store layouts, or different constraints placed on the imaging system, such as the speed of operating the system.
There remains a need for a system and method for characterizing or configuring an imaging system, such as a store shelf imaging system, so that it is adaptable to different applications.